Lead (Pb) contamination in Moso bamboo forests poses a challenge in terms of sustainable development and raises concerns about the safety of bamboo shoots for consumption. However, the physiological impacts of Pb stress on Moso bamboo growth and the molecular mechanisms governing its adaptive responses remain poorly understood. This study comprehensively investigated the physiological and transcriptomic responses of Moso bamboo to Pb stress. The results showed that low concentrations (1–10 µM) of Pb stress had minimal adverse effects on biomass accumulation and the photochemical quantum yield of PSII in Moso bamboo. However, at a high Pb concentration (50 µM), the growth of roots was significantly inhibited, while Pb accumulation in the roots and shoots reached 15,611 mg·kg−1 and 759 mg·kg−1, respectively. The uptake of Pb was increased as the external Pb concentration increased, but the xylem loading of Pb reached saturation at 57.79 µM after six-hour exposure. Pb was mainly localized in the epidermis and pericycle cells in the roots, where the thickening of cell walls in these cells was found after Pb treatment. Transcriptomic profiling identified 1485 differentially expressed genes (DEGs), with significant alterations in genes associated with metal cation transporters and cell wall synthesis. These findings collectively indicate that Moso bamboo is a Pb-tolerant plant, characterized by a high accumulation capacity and efficient xylem loading. The tolerance mechanism likely involves the transcriptional regulation of genes related to heavy metal transport and cell wall biosynthesis.